Hi to both, thanks for your responses.
I've been trying multiple permutations to see what would work. I still haven't managed much that I could consider helpful.
With the commands to create the .kc files, I made two from the release kernel with suffixes for development and debug, and the same for the development kernel. In the end I had files for release.kc.development, release.kc.debug, dev.kc.development, dev.kc.debug.
Both release versions booted no prob, the dev ones showed the same issue, where the mac sound gets played, then it connects to the network (either DCHP or a manually set one), but it doesn't take any input from external devices and displays nothing.
From there it seems to reboot itself a bunch of time, as the network connection stops working multiple times until it eventually "breaks" and forces me into a window with "The version of macOS on the selected disk needs to be reinstalled" and the option to go to recovery.
In addition to what Kevin noted in the reply, what is the output of uname -v on that host and what is the KDK build that you downloaded for it? Also, what is the name of the kernel binary file (the one from the downloaded KDK, which contains the model name) you used to generate the kext collection?
uname -v
Darwin Kernel Version 27.0.0: Tue Aug 11 21:06:15 PDT 2026; root:xnu-13432.1.9~1/RELEASE_ARM64_T8152
sw_vers
ProductName: macOS
ProductVersion: 27.0.1
BuildVersion: 26A434
I'm using KDK_27.0.1_26A434.kdk, which matches the product and build versions.
Ever since you guys' responses I've been trying to generate reports to see if I could report a bug with some substance.
Debugging hasn't really worked as well as I hoped, but since I don't have a working system I can try, I don't know if maybe I'm missing something. Basically I didn't manage to do a network debug, neither connecting two computers directly via ethernet and setting static addresses nor connecting them to a switch with DHCP worked. I thought it might be the fact that I couldn't use USB ethernet adapters, but then I borrowed another mac mini again to try it out with both ethernet ports and nothing worked anyways.
I looked into some older articles online about debugging where I could use the power button to trigger an NMI to dump the file directly into the device, without needing a second one. That also didn't work. I think I was looking for the files in the "wrong" directory (/var/tmp/kernel_panics). I was later able to find some stuff under /Library/Logs/DiagnosticReports.
At some point after the message about macOS being broken, I could open recovery and the terminal to see an .ips file. After rebooting with the high security mode in order to boot normally, the file wasn't there anymore. This is one of the refs I used the most and that seemed the most complete but nothing from there really worked: https://karol-mazurek.medium.com/kernel-debugging-setup-on-macos-07dd8c86cdb6
I replicated the steps I took to recreate and copy the .ips file to another place where it would persist, but I couldn't get it to appear anymore. Otherwise I was able to see some .shutdownStall files. I made the latest one readable, but based on the "Posting a crash report" post don't know if it's a relevant file since it's neither a crash nor an ips. It's got stuff about pci errors and drivers.
Any advice on how to proceed would be appreciated. I'm kind of at my wit's end.
Many thanks!
